Trophic niche segregation between the sexes in two species of livebearing fishes (Poeciliidae)
2011 (English)In: Bulletin of Fish Biology, ISSN 1867-5417, Vol. 13, no 1-2, 11-20 p.Article in journal (Refereed) Published
Fishes of the genus Poecilia are highly sexually dimorphic. In the two species investigated here (P. latipinna and P. mexicana) males are, on average, of smaller body size and more colorful than females. Males also differ from females in time allocated to feeding as they engage in mating behavior almost dayround. We hypothesized that, due to different time allocations and energy requirements, the sexes might forage on different food items and thus could occupy different trophic niches. We investigated gut content compositions, intestinal tract length and gut fullness in multiple populations of P. latipinna and P. mexicana. Our fi nding of females having fuller guts than males corroborated sex differences in time allocation for foraging. A major difference between sexes was also found in intestinal tract length, with males consistently having shorter guts, likely refl ecting spatial constraints due to sexually dimorphic traits (like a more anterior anal porus). Contrary to prediction, however, gut content composition indicated no clear-cut pattern of sex-specifi c trophic niches across study sites. Niche widths, on the other hand, differed between sexes with males having narrower trophic niches than females. Overall, we found sex-specifi c differences in some aspects of feeding ecology, but no clear trophic niche segregation was detected.
Place, publisher, year, edition, pages
2011. Vol. 13, no 1-2, 11-20 p.
trophic niche segregation, sexual dimorphism, gut content analysis, Poeciliidae, sexual segregation
IdentifiersURN: urn:nbn:se:uu:diva-246041OAI: oai:DiVA.org:uu-246041DiVA: diva2:791731
Title and summary in English and German2015-03-022015-03-022015-07-31Bibliographically approved